Straightening apparatus

ABSTRACT

The invention concerns an anode straightening apparatus ( 10, 30, 60 ) for the straightening of an anode ( 100 ) typically used in an electrowinning process. In the preferred embodiment the apparatus includes clamps ( 21, 41, 71 ) for clamping a busbar ( 101 ) of the anode and clamps ( 22, 42, 71 ) for clam in a blade of the anode to the apparatus during the course of the straightening process. At least one sensor ( 29, 52, 85 ) monitors the curvature of the blade ( 102 ) of the anode ( 100 ) when the anode is secured to the apparatus by the clamps. The apparatus (( 10, 30, 60 ) includes a movable head ( 24, 44, 78 ) housing straightening means for bending the anode in a desired direction in response to feedback received from the sensor. The head is movable in two planes of movement which are transverse to one another. The apparatus further has actuators ( 27, 28, 48, 49, 81, 83 ) for urging the straightening means along its axes of movement in the first and second planes respectively so that the anode may be straightened by urging the straightening means in the second plane of movement while moving it in the first plane of movement. The invention also concerns a method of straitening an anode ( 100 ) by first bending the anode into a pre-set curvature and there-after bending it to a theoretically correct curvature, which is preferably a zero curvature.

BACKGROUND TO THE INVENTION

This invention relates to a straightening apparatus. In particular, but not exclusively, this invention relates to a straightening apparatus for the straightening of an anode used in an electrowinning process.

Copper ore is mostly found in two forms, namely sulphide ore and oxide ore. Sulphide ores are beneficiated in flotation cells and oxide ores are generally leached. First the copper ore from an open pit mine is blasted, loaded and transported to primary crushers. There the ore is crushed and screened, with the fine sulphide ore going to froth flotation cells for the recovery of copper. The coarser ore goes through a heap leaching process, where the copper is subjected to a dilute sulphuric acid solution to dissolve the copper.

Then the leach solution containing the dissolved copper is subjected to a process called solvent extraction which concentrates and purifies the copper leach solution so that the copper can be recovered in electrowinning cells. The copper solution is dissolved in sulphuric acid and sent to electrolytic cells for recovery as copper plates which form on the cathodes of the cells. The copper is then removed from the cathodes and manufactured into products suitable for everyday use.

Anodes used in electrowinning cells are usually in the form of cast lead alloy plates attached to copper busbars through which electrical contact and thus electron flow is achieved. The cast alloy plate, also commonly referred to as the blade, is generally of rectangular shape and extends from the busbar. After manufacturing the anodes are packed in batches on pallets for transportation and storage. A major problem currently being experienced in this field is that during this period creep occurs in the blade of the anode and as a result it bends under its own weight to an undesired curvature. This undesired curvature can cause the anode to have either poor electrical conductivity through the offset contact of the busbar to an electrical terminal of the cell or to create a short circuit through contact with a cathode. Another problem currently being experienced is with the occurrence of work deformation, which also results in an undesired and incorrect curvature.

It is accordingly an object of the invention to provide a straightening apparatus for the straightening of an anode that will, at least partially, address the above problems.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided an anode straightening apparatus including:

-   -   at least one clamp for clamping the anode to the apparatus         during the course of the straightening process;     -   at least one sensor for monitoring the curvature of a blade         portion of the anode when the anode is secured to the apparatus         by the clamp;     -   straightening means for bending the anode in a desired direction         in response to feedback received from the sensor, the         straightening means being movable in two planes of movement         which are transverse to one another; and     -   actuators for urging the straightening means along its first and         second axes of movement in the first and second planes         respectively so that the anode may be straightened by urging the         straightening means in the second plane of movement while moving         it in the first plane of movement.

In the preferred embodiment the first and second planes are perpendicular to one another. For example, the first plane may be vertically oriented and the second plane horizontally oriented such that the straightening means are movable back and forth in both vertical and horizontal directions.

The straightening apparatus may include a securing mechanism for securing the end of the anode which is, in use, the lower end. The securing mechanism preferably has two guide members which are arranged to receive the end of the anode in a gap between them.

Preferably, the straightening means includes a set of rollers which is located in a movable head and arranged so that the rollers are, in use, located on either side of the anode such that when the rollers are moved in the first plane of movement they run on opposite sides of the anode blade. In one embodiment of the apparatus, the head is mounted on a carrier frame which is movable in the first plane of movement while the head is movable with respect to the carrier frame in the second plane of movement.

The anode straightening apparatus may include four actuators, two of which may be arranged so that their axes of movement lie in the first plane for urging the straightening means along the first axis of movement and two of which may be arranged so that their axes of movement lie in the second plane for urging the straightening means along the second axis of movement.

The actuators may be in the form of servo drives or hydraulic actuators. Where hydraulic actuators are use, they are preferably in the form of double acting piston and cylinder assemblies.

The anode straightening apparatus may have at least three sensors which are movable together with the straightening means. The sensors are preferably spaced apart for scanning different regions of the anode blade. In one embodiment the apparatus has four sensors which are provided in a linear arrangement.

In the preferred embodiment, the anode straightening apparatus includes two pairs of anode clamps with one pair of clamps being arranged to clamp a top edge of the anode and the other pair of clamps being arranged to clamp a blade portion of the anode. Preferably, the clamps are in the form of extendible hydraulic piston and cylinder assemblies.

The anode straightening apparatus preferably has a control panel and PLC for controlling the movement of the straightening means in an automated manner in response to feedback received from the at least one sensor.

According to a second aspect of the invention there is provided a method of straightening an anode, the method including the steps of:

-   -   aligning the anode in a straightening apparatus;     -   clamping the anode to the straightening apparatus to secure it         thereto;     -   scanning the anode to detect any variations from a theoretically         correct curvature using at least one sensor;     -   bending the anode into a pre-set curvature by urging         straightening means into a calculated direction; and     -   bending the anode into the theoretically correct curvature in         response to the feedback received from the sensor.

The steps of scanning and bending the anode in response to the feedback received from the sensor are preferably repeated until the curvature of the anode corresponds with the theoretically correct curvature.

Preferably, the theoretically correct curvature is one which corresponds with a substantially zero curvature so that the straightening process is automatically terminated only once the anode is straight.

The step of bending the anode into a pre-set curvature may include moving the straightening means in a first and second plane of movement which are transverse to one another. The first plane may be a vertical plane and the second plane may be a horizontal plane so that the straightening means are moveable back and forth in both vertical and horizontal directions.

The method may further include the step of securing the end of the anode which is, in use, the lower end.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 shows a perspective view of a first embodiment of a straightening apparatus according to the invention;

FIG. 2 shows a front view of the apparatus of FIG. 1;

FIG. 3 shows a side view of the apparatus of FIG. 1;

FIG. 4 shows a top view of the apparatus of FIG. 1;

FIG. 5 shows a perspective view of a drive assembly of the apparatus of FIG. 1;

FIG. 6 shows a perspective view of the drive assembly of FIG. 5 wherein an anode is mounted therein;

FIG. 7 shows a front perspective view of a second embodiment of a straightening apparatus according to the invention;

FIG. 8 shows a rear perspective view of the apparatus of FIG. 7;

FIG. 9 shows a front view of the apparatus of FIG. 7;

FIG. 10 shows a side view of the apparatus of FIG. 7;

FIG. 11 shows a top view of the apparatus of FIG. 7;

FIG. 12 shows a front perspective view of a drive assembly of the apparatus of FIG. 7;

FIG. 13 shows a rear perspective view of a drive assembly of the apparatus of FIG. 7;

FIG. 14 shows a front perspective view of a third embodiment of a straightening apparatus according to the invention;

FIG. 15 shows a rear perspective view of the apparatus of FIG. 14;

FIG. 16 shows a front view of the apparatus of FIG. 14;

FIG. 17 shows a side view of the apparatus of FIG. 14;

FIG. 18 shows a top view of the apparatus of FIG. 14;

FIG. 19 shows a front perspective view of a drive assembly of the apparatus of FIG. 14; and

FIG. 20 shows a rear perspective view of a drive assembly of the apparatus of FIG. 14.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Referring to the drawings, in which like numerals indicate like features, non-limiting examples of an anode straightening apparatus in accordance with the invention is generally indicated by reference numerals 10, 30 and 60.

FIG. 1 shows a first embodiment of a straightening apparatus 10 for straightening an anode 100 (visible in FIG. 6) according to the invention. A person skilled in the art of extracting copper from ore using an electrowinning process will be familiar with the shape and configuration of the anode 100. As a result it is only briefly described herein. The anode 100 is commonly of rectangular shape and comprises a top elongate section 101 forming a busbar and a cast alloy lead blade section 102 extending from the top section. The ends of the busbar 101 extend beyond the width of the blade 102.

Returning now to FIG. 1 it can be seen that the apparatus 10 includes a frame assembly 11 defining a housing in which a drive assembly 20 (FIG. 4) is located and a handrail assembly 12 mounted on the housing. As can be seen in FIG. 1, the handrail assembly 12 includes a ladder 13 arranged so that a person can access the top of the housing to assist with the feeding of the anode to the drive assembly 20 inside the housing. The front and side views of the apparatus 10 are shown in FIGS. 2 and 3 respectively.

A cover plate 14, which in use is the top plate of the housing 11, has a slot 15 therein. The slot 15 provides access for the anode 100 into the housing so that it may be mounted in the drive assembly 20.

The drive assembly 20 is shows in perspective view in FIG. 5 and includes at least one clamp for clamping the anode 100 to the apparatus, ad in particular the drive assembly, during the course of the straightening process. In the illustrated embodiment the drive assembly includes two anode clamps 21.1 and 21.2 which are arranged to clamp the blade 102 when the anode is located in the drive assembly. Two separate busbar clamps 22.1 and 22.2 are used to clamp the ends of the busbar 101.

In the first illustrated embodiment all of the clamps comprise hydraulic piston and cylinder assemblies.

A securing mechanism 23 is located to grip an end region, which in use is a lower region, of the blade 102 when the anode is located in the drive assembly. The securing means 23 has two guide members in the form of rollers 23.1 and 23.2 which are arranged relative to one another to receive the anode between them. It must be understood that the rollers 23.1 and 23.2 are spaced apart from one another at such a distance that the anode fits securely between them, thereby securing the lower end of the blade in a direction which is substantially a horizontal direction in the drawings. This prevents the lower end of the anode 100 from moving around once the anode is mounted in the drive assembly 20.

It must be clear that the securing mechanism 23 align the anode blade 102 with the busbar 101 at the top of the anode to ensure that the anode is properly aligned prior to initiating the straightening process, irrespective of the curvature of the blade.

The drive assembly 20 includes a movable head 24 which houses straightening means for straightening the anode 100. In the preferred embodiment, the straightening means includes two rollers 25.1 and 25.2 which are located in the head and spaced apart so that in use the rollers are located on either side of the anode blade 102. In the straightening process the rollers are used to straighten the anode 100 using a rolling process i.e. by rolling up and down the blade 102.

The head 24, and therefore the rollers 25, is movable in two planes of movement that are transverse to one another. In the accompanying drawings the axes of movement of the head 24 lie in the vertical and horizontal planes. The first, vertical axis of movement is indicated in the drawings by reference numeral 26.1 and the second, horizontal axis of movement by 26.2. It must be understood that the references to the vertical and horizontal axes of movement refer to the embodiments shown in the drawings and that the planes in which the rollers are moved do not necessarily have to be vertical and horizontal. In other embodiments (not illustrated in the drawings) the blade 102 may be mounted in the drive assembly in such a manner that the blade does not lie in a vertical plane the axes of movement of the rollers would not necessarily be vertical and horizontal.

In order to move the head 24, the drive assembly 20 includes actuators which are operable to cause the head to move along the first and second axes of movement. As shown in FIGS. 5 and 6, the head 24 is mounted between two linear actuators 27.1 and 27.2 arranged substantially horizontally, thereby causing the head to move along the second axis when actuated. The actuators 27.1 and 27.2 are in turn mounted on two linear actuators 28.1 and 28.2 which are arranged substantially vertically, thereby causing the head to move along the first axis when activated.

In the embodiment 10 of the straightening apparatus, the actuators are in the form of servo drives to ensure accurate, automated movement of the rollers 25.1 and 25.2. Typically the servo drives are capable of achieving a repeatability of less than 0.5 mm.

Both sets of actuators are in use activated in response to the feedback received from at least one sensor, which monitors the curvature of the anode blade 102. To improve accuracy of the sensor readings, the first illustrated embodiment includes three sensors 29.1, 29.2 and 29.3 arranged in a triangular arrangement on the head 24. Two sensors 29.1 and 29.2 are located above the rollers 25 and the other sensor 29.3 below the rollers. In use, the top two sensors 29.1 and 29.2 scan the edges of the anode blade 102 above the location of the rollers while the bottom sensor 29.3 scan the middle of the blade below the rollers.

The sensors 29 are used to scan the curvature of the blade 102 during the entire straightening process. The feedback received from the sensors is relayed back to a PLC coupled with a panel mounted computer located in compartment 16. This feedback is then used to control the movement of the head 24 and accordingly the rollers 25.1 and 25.2 by manipulating the actuators.

The method of straightening the anode blade 102 will now be explained in greater detail. The anode 100 is normally loaded into the apparatus 10 by means of an electrical hoist, for example a jib crane, and secured in the drive assembly 20 by the blade clamps 21.1, 21.2 and busbar clamps 22.1, 22.2 once the blade 102 has been aligned as described above. Once the anode 100 is clamped in position and aligned in the drive assembly 20, the operator starts the automated rolling process by pressing a start button to activate the PLC. Upon activation of the PLC the apparatus 10 will proceed to bend the blade 102 to a pre-set curvature. The blade will typically be plastically deformed into the pre-set curvature. A skilled person will know that by first rolling the blade 102 to a pre-set curvature, the correcting process is simplified. Once the blade 102 corresponds with the pre-set curvature, the actual correcting process starts, during which the blade 102 is bent into a pre-set, theoretically correct curvature. It must be understood that this is done by urging the straightening means into the direction in the horizontal plane of movement opposite to the direction in which it was urged in the previous step while moving it up and down the vertical plane of movement. During the correcting process, the sensors 29 scan the blade 102 continuously and the feedback is used to control the movement of the rollers 25.1 and 25.2 to ensure that any deviations from the theoretically correct curvature are automatically corrected. The apparatus automatically stops the correcting process once the anode is straight i.e. when feedback from the sensors reports no deviation from the theoretically correct curvature.

It must be understood that the pre-set theoretically correct curvature is one which corresponds with a substantially zero curvature, thereby to ensure that the correcting or straightening process only terminates once the anode is straight.

Turning now to FIG. 7, a second embodiment of an anode straightening apparatus in accordance with the invention can be seen. In this embodiment, movement of the head is achieved through hydraulic actuators as opposed to the servo drives of the first embodiment. The hydraulic actuators are described in greater detail below. The second embodiment is indicated by the reference numeral 30.

From FIG. 7 it can be seen that the apparatus 30 has a raised platform 31 on which the operator stands when operating the apparatus. The compartment 16 housing the control panel, which includes the PLC and HMI (human-machine interface), is located at a level where it can easily be accessed by the operator while standing on the platform. Similarly to the first embodiment, the platform 31 is accessed by means of the ladder 13. An hydraulic power pack 32 for operating the hydraulic actuators is located underneath the platform 31.

The apparatus 30 also includes a frame assembly 33 in which a drive assembly 40 is located. The top of the frame assembly is covered by a cover plate 34 in which a slot 35 is located through which the anode 100 is, in use, received. Although the frame assembly 33 of the second embodiment 30 is shown without cover plates forming an enclosed housing such as that shown in FIGS. 1 to 4, it is envisaged that it could be enclosed for safety reasons should this be required.

Turning now to FIG. 12, the drive assembly of the second embodiment 30 of the straightening apparatus is illustrated by the reference numeral 40. Similarly to the first embodiment the drive assembly 40 includes four clamps for clamping the anode thereto. The clamps 41.1 and 41.2 in use clamp the busbar 101 while the clamps 42.1 and 42.2 clamp the blade 102 of the anode. All of the clamps are hydraulically operated and include piston and cylinder assemblies.

The lower end of the anode blade is again secured by means of a securing mechanism 43. Instead of the rollers of the first embodiment, the guide members of the securing mechanism 43 are in the form of two plates which define a V shaped guide for guiding the anode blade 102 into the gap between them.

Once the anode is secured in the drive assembly 40, the straightening of the blade is again achieved by means of straightening means mounted on a movable head 44. The straightening means is again in the form of two spaced apart rollers 45.1 and 45.2 as described above with reference to the first embodiment 10. The head 44 and therefore the rollers 45.1 and 45.2 are movable along the first and second axes of movement referred to above and indicated by the reference numerals 26.1 and 26.2 respectively.

In the second embodiment 30 of the straightening apparatus the head 44 is movably mounted on a carrier frame 46. The head 44 is movable with respect to the carrier frame along the second axis of movement, i.e. in a horizontal plane in the accompanying drawings, thereby allowing the rollers 45.1 and 45.2 to be movable along the horizontal axis. As mentioned above, movement of the head 44 is achieved by means of hydraulic actuators. Two actuators in the form of double-acting piston and cylinder assemblies 47.1 and 47.2 urge the head 44 back and forth along the second, horizontal axis of movement 26.2.

To provide additional stability, the head 44 is mounted to the carrier frame 46 using two stationary guide shafts 48.1 and 48.2. As can be seen from FIG. 12, the guide shafts are located at opposite ends of the header 12 and run substantially parallel to the axis of extension and contraction of the hydraulic actuators 47.1 and 47.2.

In order to move the head 44 along the first axis of movement 26.1, i.e. In a vertical plane in the accompanying drawings, the carrier frame 46 is movably mounted with respect to the outer frame 33 of the apparatus 30. Two actuators in the form of double-acting piston and cylinder assemblies 49.1 and 49.2 urge the carrier frame 46, together with the head 44 mounted thereon, back and forth along the first, vertical axis of movement 26.1. Each of the hydraulic actuators carries connecting formations 50 at their ends for connecting them to the outer frame 33. In the second embodiment illustrated in the drawings the connecting formations are bolted to the outer frame 33.

Two pairs of stationary guide shafts 50.1 and 50.2 provide stability to the carrier frame 46 when moving along the vertical plane. The pairs of guide shafts are connected to the outer frame 33 at opposite ends of the carrier frame 46 and run substantially parallel to the axis of extension and contraction of the hydraulic actuators 49.1 and 49.2.

It must be clear that the head 44 and carrier frame 46 simply slides along their respective guide shafts as the associated hydraulic actuators are extended and contracted. From FIGS. 12 and 13 it can be seen that the two pairs of vertical guide shafts 50.1 and 50.2 also act as mounting means onto which other components, such as the securing formation 43 and clamps, are mounted.

The method of straightening the anode 100 using the second embodiment 30 of the apparatus is similar to that of the first embodiment. However, the triangularly arranged sensors of the first embodiment have been replaced by a linear series of sensors 52. In the embodiment illustrated in FIGS. 7 to 13, the sensors are aligned linearly on top of the head 44 where they independently scan the curvature of different regions of the blade 102 of the anode.

A third embodiment of the straightening apparatus in accordance with the invention is illustrated in FIGS. 14 to 20 and indicated by the reference numeral 60. The third embodiment 60 is similar to the second embodiment 30 and also includes hydraulic actuators to manipulate the movement of the straightening means. From the accompanying drawings it can be seen that the structural design of the third embodiment has been simplified when compared to the second embodiment in an attempt to reduce manufacturing and maintenance costs.

Referring now to FIG. 14, it can be seen that the compartment 16 is located underneath the raised platform 61 on which the operator stands when operating the apparatus 60. Similarly to the previous embodiments the apparatus 60 also includes a drive assembly 70 which is located in the frame assembly 63. The top of the frame assembly is covered by a cover plate 64 in which a slot 65 is located through which the anode 100 is, in use, received. The HMI (human-machine interface) panel is located on the top panel 64 on the outer frame 63 where it can easily be accessed by the operator while standing on the platform. The illustrated position of the HMI panel allows the operator to face towards the apparatus 60 while operating it, thereby improving safety as visual surveillance is maintained during the entire straightening process. For safety purposes it is again envisaged that the outer frame 63 could be enclosed with cover plates should this be required.

FIG. 19 shows a perspective view of the drive assembly 70 of the third embodiment 60 of the straightening apparatus. The drive assembly 70 again includes four clamps for clamping the anode 100 thereto. In use, the clamps 71.1 and 71.2 clamp the busbar 101 while the clamps 72.1 and 72.2 clamp the blade 102 of the anode. All of the clamps are hydraulically operated and include piston and cylinder assemblies.

In this embodiment of the straightening apparatus, the busbar clamps 72.1 and 72.2 are movable to allow anodes of different sizes to be clamped in the apparatus 60. Referring still to FIG. 19 it can be seen that the busbar clamps are mounted on a mounting formation 73 which is in use carried by the outer frame 63 and, in particular, by the top cover 64 thereof (as shown in FIGS. 16 and 17). In the embodiment illustrated in FIG. 19 the busbar clamps 71,1 and 71.2 are bolted to the mounting formation 73 which has connecting slots 74 along which the clamps may be moved in order to mount them in the desired position. The slots 74 run along the first axes of movement, i.e. vertically, so that the positions of the clamps may be adjusted vertically.

In this embodiment, the securing mechanism 75, which secures the lower end of the anode blade 102, include two wedges 76 which define a V shaped guide for guiding the anode blade into the gap between them. The wedges 76 are mounted on two spaced apart feet 77 which, in turn, are mounted on the floor of the outer frame 62. It is envisaged that by using slots on the wedges 76 and feet 77 the positions of the wedges are adjustable in both the first and second planes of movement, thereby to accommodate different sized anode blades. In use, fasteners such as bolts, for example, may be used to secure the wedges to the feet.

The straightening of the blade is again achieved by means of straightening means mounted on a movable head 78 which is movable along the first and second axes of movement referred to above and indicated by the reference numerals 26.1 and 26.2 respectively. The straightening means is again in the form of two spaced apart rollers 79.1 and 79.2 as described above with reference to the first and second embodiments 10 and 30.

The head 78 is again carried by a carrier frame 80 in such a manner that it is movable with respect to the carrier frame along the second axis of movement, i.e, in a horizontal plane in the accompanying drawings, thereby allowing the rollers 79.1 and 79.2 to be movable in the horizontal direction.

Two actuators in the form of double-acting piston and cylinder assemblies 81.1 and 81.2 urge the head 78 back and forth along the second, horizontal direction of movement 26.2. In this embodiment, the cylinder and piston assemblies have been designed so that the head 78 may be carried by them without the need of guide shafts. As a result, the head 78 is mounted directly on the cylinders. Both ends of the actuators carry connectors so that the actuators can be secured on the carrier frame 80. In the drawings, the connectors are illustrated as threaded portions which extend through holes in the carrier frame 80 and then secured thereto by means of nuts 82.

In order to move the head 78 along the first axis of movement 26.1, i.e. in a vertical plane in the accompanying drawings, the carrier frame 80 is movably mounted with respect to the outer frame 63 of the apparatus 60. Again, two actuators in the form of double-acting piston and cylinder assemblies 83.1 and 83.2 urge the carrier frame 80, together with the head 78 mounted thereon, back and forth along the first, vertical axis of movement 26.1. The need for guide shafts is again eliminated by designing the actuators 83.1 and 83.2 such that the carrier frame 80 is carried entirely by them.

Each of the hydraulic actuators carries connecting formations in the form of threaded portions at their ends for connecting them to the outer frame 63. As shown in FIGS. 14 and 15, the threaded ends of the actuators 83.1 and 83.2 are secured to the outer frame 63 by means of nuts 84.

Similarly to the second embodiment, the head 78 carries a linear series of sensors 85 where they independently scan the curvature of the blade 102 of the anode. The method of straightening the anode 100 using the third embodiment 70 of the apparatus is similar to that using the first and second embodiments described above.

It must be understood that although the straightening apparatus 10, 30, 60 has been described above for straightening anodes used in electrowinning cells, it is not limited to this specific application only. It is envisaged that the straightening apparatus in accordance with this invention could also be used for straightening other blade-like objects by making minor variations to it without departing from the spirit and scope of the invention. 

1. An anode straightening apparatus including: at least one clamp for clamping the anode to the apparatus during the course of the straightening process; at least one sensor for monitoring the curvature of a blade portion of the anode when the anode is secured to the apparatus by the clamp; straightening means for bending the anode in a desired direction in response to feedback received from the sensor, the straightening means being movable in two planes of movement which are transverse to one another; and actuators for urging the straightening means along its first and second axes of movement in the first and second planes respectively so that the anode may be straightened by urging the straightening means in the second plane of movement while moving it in the first plane of movement.
 2. An anode straightening apparatus according to claim 1, wherein the first and second planes are perpendicular to one another.
 3. An anode straightening apparatus according to claim 2, wherein the first plane is vertically oriented and the second plane is horizontally oriented such that the straightening means are movable back and forth in both the vertical and horizontal directions.
 4. An anode straightening apparatus according to any one of claims 1 to 3, including a securing mechanism for securing the end of the anode which is, in use, the lower end.
 5. An anode straightening apparatus according to claim 4, wherein the securing mechanism includes two guide members which are arranged to receive the end of the anode in a gap between them.
 6. An anode straightening apparatus according to any one of claims 1 to 5, wherein the straightening means includes a set of rollers which is located in a movable head and arranged so that the rollers are, in use, located on either side of the anode such that when the rollers are moved in the first plane they run on opposite sides of the anode blade.
 7. An anode straightening apparatus according to claim 6, wherein the head is mounted on a carrier frame which is movable in the first plane of movement, the head being movable with respect to the carrier frame in the second plane of movement.
 8. An anode straightening apparatus according to any one of claims 1 to 7, including four actuators, two of which are arranged so that their axes of movement lie in the first plane for urging the straightening means along the first axis of movement and two of which are arranged so that their axes of movement lie in the second plane for urging the straightening means along the second axis of movement.
 9. An anode straightening apparatus according to claim 8, wherein the actuators are in the form of servo drives or hydraulic actuators.
 10. An anode straightening apparatus according to claim 9, wherein the hydraulic actuators are in the form of double acting piston and cylinder assemblies.
 11. An anode straightening apparatus according to any one of claims 1 to 10, including at least three sensors which are movable with the straightening means, wherein the sensors are spaced apart for scanning different regions of the anode blade.
 12. An anode straightening apparatus according to claim 11, wherein four sensors are provided in a linear arrangement.
 13. An anode straightening apparatus according to any one of claims 1 to 12, including two pairs of anode clamps with one pair of clamps being arranged to clamp a top edge of the anode and the other pair of clamps being arranged to clamp a blade portion of the anode.
 14. An anode straightening apparatus according to claim 13, wherein the clamps are in the form of extendible hydraulic piston and cylinder assemblies.
 15. An anode straightening apparatus according to any one of claims 1 to 14, including a control panel and PLC for controlling the movement of the straightening means in an automated manner in response to feedback received from the at least one sensor.
 16. A method of straightening an anode, the method including the steps of: aligning the anode in a straightening apparatus; clamping the anode to the straightening apparatus to secure it thereto; scanning the anode to detect any variations from a theoretically correct curvature using at least one sensor; bending the anode into a pre-set curvature by urging straightening means into a desired direction; and bending the anode into the theoretically correct curvature in response to the feedback received from the sensor.
 17. A method according to claim 15, wherein the steps of scanning and bending the anode in response to the feedback received from the sensor are repeated until the curvature of the anode corresponds with the theoretically correct curvature.
 18. A method according to either claim 15 or 16, wherein the theoretically correct curvature is one which corresponds with a substantially zero curvature so that the straightening process is automatically terminated only once the anode is straight.
 19. A method according to any one of claims 15 to 17, wherein the step of bending the anode into a pre-set curvature includes moving the straightening means in a first and second plane of movement which are transverse to one another.
 20. A method according to claim 18, wherein the first plane is a vertical plane and the second plane is a horizontal plane so that the straightening means are moveable back and forth in both vertical and horizontal directions.
 21. A method according to any one of claims 15 to 19, including the step of securing an end of the anode which is, in use, the lower end. 